1 What's the tallest animal in the world? The giraffe is. They are as tall as a two-story building. Being tall helps them get food. Giraffes eat leaves from trees. They like to eat fruit, too, from the treetops. Even baby giraffes are tall. When first born, a calf is six feet tall!2 Giraffes have four long legs. Front legs are longer than the back legs. Giraffes have very long necks. Giraffes are mammals. Mammals have hair or fur. A mother mammal feeds her baby milk from her body.